Simplify the following expression: $p = \dfrac{n}{4} + \dfrac{n}{10}$
In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $4$ and $10$ $\lcm(4, 10) = 20$ $ p = \dfrac{5}{5} \cdot \dfrac{n}{4} + \dfrac{2}{2} \cdot \dfrac{n}{10} $ $p = \dfrac{5n}{20} + \dfrac{2n}{20}$ $p = \dfrac{5n +2n}{20}$ $p = \dfrac{7n}{20}$